Acetone → HCID 58700604, compound

HRID 2215886Notes

Reaction equation

HRID 2215886 reaction equation
[C:1]1(=[O:7])[CH2:5][CH:4]=[CH:3]C1=O.[C:8]([O-:11])([O-])=O.[K+].[K+].[CH3:14]OS(OC)(=O)=O.[CH3:21][C:22]([CH3:24])=[O:23]>>[CH3:14][O:23][C:22](=[C:24]1[C:8](=[O:11])[C:4]([CH3:3])=[CH:5][C:1]1=[O:7])[CH3:21]

Participants

5

Reactant 4

HCID 180AcetoneHCID 6497Dimethyl SulfateHCID 11430Potassium CarbonateHCID 185654Cyclopent-3-ene-1,2-dione

Product 1

HCID 58700604HCID 58700604, compound

Procedure

To a heated solution of the above cyclopentenedione compound (130 mg, 0.855 mmol) and K2CO3 (0.9 g) in dry acetone (20 mL) was added Me2SO4 (0.4 mL). After refluxing for 5 hr, the reaction mixture was filtered to remove K2CO3. The filtrate is concentrated to dryness; and the residue is subjected to reversed phase RP-18 column chromatography using aqueous MeOH. The 80% MeOH eluate was concentrated to dryness; and the residue was chromatographed on silica gel eluting with hexane-EtOAc (5:1 to 2:1) to give 2-(1-methoxy-ethylidene)-4-methyl-cyclopent-4-ene-1,3-dione (6) as two separable isomers in a yellow powder form (32 mg each, 46%). However, the NMR indicated that each of them behaved like coruscanone A, reaching an almost 1:1 equilibrium of two geometric isomers in solution. 1H NMR (400 MHz, CDCl3, one isomer) d 6.52 (br s, H-5), 3.94 (s, OMe), 2.54 (br s, vinylic Me), 1.95 (s, Me-4); 13C NMR (100 MHz, CDCl3, one isomer) d 194.5 and 193.0 (1,2-C═O), 173.6 (vinylic C), 155.2 (C-4), 139.7 (C-5), 107.1 (C-2), 55.9 (OMe), 14.0 (vinylic Me), 10.8 (Me-4); HRTOFMS m/z [M+H]+ 167.0682 (calcd for C9H11O3, 167.0703).

Workup

  1. temperatureAfter refluxing for 5 hr
  2. filtrationthe reaction mixture was filtered
  3. customto remove K2CO3
  4. concentrationThe filtrate is concentrated to dryness
  5. concentrationThe 80% MeOH eluate was concentrated to dryness
  6. customand the residue was chromatographed on silica gel eluting with hexane-EtOAc (5:1 to 2:1)

Sources & evidence

ORD record
ord-d20399b0eb17444680ea995a8c382438
Source dataset
uspto-grants-2006_09
Patent number
US07109380B2

Reaction notes

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